1. Field of the Invention
The invention relates to a matrix pin print head, in particular a serial matrix pin print head, which is disposed at a pin stroke distance opposite to a substrate support, where an imprint-receiving substrate rests on the substrate support, and where an ink ribbon is guided in front of the imprint-receiving substrate. The pin print head comprises a print-pin guide casing and a print-pin drive casing, where an electromagnetic drive is disposed in the print-pin drive casing and is coordinated to each print pin or impact pin. The electromagnetic drive comprises a magnet yoke. An electromagnetic coil is disposed at one magnet yoke arm of the magnet yoke. The electromagnetic drive further comprises an armature, which can be pivoted based on a pin bearing and which can rest in a rearward position against a stop based on a spring. An operating air gap is formed between the armature and a front face of the magnet yoke arm.
The invention further relates to a method for the production of an electromagnetic drive for matrix print heads, in particular for serial matrix pin print heads, where the electromagnetic drive comprises in each case a magnet yoke, an electromagnetic coil disposed on one yoke arm of the magnet yoke, and an armature which is pivotable based on a pin bearing.
2. Brief Description of i& Background of the Invention Including Prior Art
In order to generate a high number per unit of time of print dots with the ends of the print pins or impact pins, the armatures of such matrix print heads can be attracted to be positioned in a rapid sequence against the pole faces of the magnet yokes and can be released back into a rest position. The frequency of such matrix print heads has reached by now about 2000 Hz and it is desired to further increase this frequency to at least 3000 Hz for each print element. Because of the high frequencies, such matrix print heads are employed in printers for a high data output furnished by computers.
A matrix print head is known from the U.S. Pat. No. 4,242,004, which exhibits the features of the matrix print head recited above. It is further known to attach an impact pin to a spring arm, which allows to obtain a particular kinematic situation in contrast to the teaching of U.S. Pat. No. 4,242,004. This latter construction, where the impact pin is attached to the spring arm, requires however a very broad armature and is consequently not suitable for the structure of an 18-pin or 24-pin print head. Moreover, the known print head is disadvantageous for a production which requires a reliance on necessary precision and uniformity.